Room header avatar color does not match avatar color in the timeline

### Steps to reproduce

1. Open a room

### Outcome

#### What did you expect?

For the avatar to have the same colour

#### What happened instead?


### Your phone model

_No response_

### Operating system version

_No response_

### Application version

_No response_

### Homeserver

_No response_

### Will you send logs?

No

Start by reproducing the mismatch after opening a room on iOS, then compare the avatar color shown in the room header with the one used in the timeline. Done means both avatars consistently display the same color; the issue provides no file, test, device, OS, or application version to narrow the investigation.

Written by the indexing model from the issue text.